The present invention relates, in general, to network communication and, more particularly, to establishing communication between a microprocessor and a network.
Electronic devices are widely used in various aspects of daily life. Many electronic devices, such as those found in mobile telephones, automobiles, vending machines, utility meters, security systems, medical monitoring systems, etc., include microprocessors such as, for example, embedded microcontroller units (MCUs) for performing different functions and processes. It is often desirable to connect the MCU in an electronic device to a network such as Internet, so that the operation of the electronic device can be remotely monitored and/or controlled.
One approach for connecting a microprocessor such as an MCU to a network is to program a network protocol, e.g., Transmission Control Protocol/Internet Protocol (TCP/IP), into the MCU. An MCU with TCP/IP programmed therein can access Internet through a modulation and demodulation device (MODEM). This approach normally needs an MCU of at least 16 bits. It also needs a large memory, e.g., at least 32 kilo-bytes, and a high operating speed in order to achieve a satisfactory performance. Furthermore, the engineers who program the MCU chip must be familiar not only with the applications of the MCU but also with the TCP/IP protocol and related interfaces. Therefore, this approach usually requires a long development period, a high performance chip, and is cost inefficient.
Another approach for connecting a microprocessor such as an MCU to a network is to establish a network interface, e.g., an interface developed by emWare, Inc. under the trademark xe2x80x9cemGatewayxe2x80x9d, off chip and program a network interface compatible protocol, e.g., a protocol developed by emWare, Inc. under the trademark xe2x80x9cemNetxe2x80x9d, into the MCU chip. An MCU with emnet programmed therein can access Internet via the network interface emGateway. Although emNet requires less memory than TCP/IP, this approach still requires the design engineers to be familiar not only with the application of the MCU but also with the emNet and related interfaces. Furthermore, the existing MCU chips in a user""s application systems may not satisfy the designer""s expectation because of chip capability, memory, speed, etc. Therefore, this approach often also requires a long development period, a relatively high performance chip, and is cost inefficient.
Accordingly, it would be advantageous to have a cost efficient method for communicating between a microprocessor and a network. It is desirable for the method to be simple and reliable. It is also desirable for the method to be compatible with different types of microprocessors in terms of capabilities, performances, costs, etc. It is especially desirable for the method to be compatible with a user""s existing microprocessor chips. It would be of further advantage to have a simple, reliable, and cost efficient apparatus to implement the method.
A prime advantage of the present invention is to provide a simple and cost efficient process for communicating between a microprocessor and a network. Another advantage of the present invention is to provide a simple, reliable, and cost efficient apparatus to implement the communication process. A further advantage of the present invention is to provide the communication process capable of establishing communications between the network and microprocessors with wide spectra of applications, capabilities, performances, bit numbers, memory sizes, etc. In addition, a particular advantage of the present invention is that the communication process can be readily implemented with an existing microprocessor chip.
In order to achieve these and other advantages of the present invention, a method for communicating between a microprocessor and a network is implemented by first coupling the microprocessor to a signal adapter. The signal adapter includes a signal processing unit and a memory unit coupled to the signal processing unit. A communication protocol is stored in the memory unit. The signal adapter also has an interpreter stored in the memory unit. The interpreter is compatible with the programming language, e.g., C, C++, an assembly language, etc., of the microprocessor. The signal adapter functions as an intermediary between the network and the microprocessor.
A signal in the network typically follows a network protocol. For example, a signal in the Internet typically follows Transmission Control Protocol/Internet Protocol (TCP/IP). Preferably, a signal in the network is sent to the microprocessor through a network interface and the signal adapter. The network interface, such as an interface developed by emWare, Inc. under the trademark xe2x80x9cemGatewayxe2x80x9d, coverts the signal from TCP/IP to a network protocol, such as a protocol developed by emWare, Inc. under the trademark xe2x80x9cemNetxe2x80x9d, compatible with the communication protocol on the signal adapter. The signal adapter identifies, interprets, and reformats the signal received from the network interface into a microprocessor acceptable signal, e.g., a signal in a format compatible with C, C++, an assembly language, etc. Depending on the signal, the signal adapter can execute the reformatted signal and/or send the reformatted signal to the microprocessor. The signal adapter can also ignore the reformatted signal.
Depending on the signal received from the signal adapter, the microprocessor can either execute or ignore the received signal. If the execution of the signal by the microprocessor requires the microprocessor to send a return signal back to the network, the return signal is sent to the signal adapter according to a format acceptable to the signal adapter. The signal adapter identifies, interprets, and reformats the return signal in accordance with the communication protocol and sends it to the network interface. The network interface converts the signal into the network protocol sends it to the network.
The signal adapter of the present invention can establish communications between networks and microprocessors of various capabilities, performances, bit numbers, and memory sizes. It is compatible with microprocessors having as little as four bits. It does not occupy memories on the microprocessor. It does not require significant modifications of the programming structure or the physical structure of existing microprocessors in a user""s application systems. The designers of the microprocessors are not required to be familiar with the network protocol. By communicating with a network, e.g., Internet, via a network interface, e.g., emGateway, the communication protocol on the signal adapter can be simple and memory space efficient. Therefore, the signal adapter of the present invention is simple, reliable, and cost efficient.